Obviously it shouldn't resolve if there's an error

back-end/available_serial_ports.js

@@ -4,7 +4,7 @@ module.exports = function getAvailablePorts(){
     return new Promise(function(resolve, reject){
         serialport.list(function (err, ports) {
             if(err) reject(err);
-            resolve(ports.map(p => { return p.comName }));
+            else resolve(ports.map(p => { return p.comName }));
         });
   });
 };